Reduced-pressure systems, dressings, and methods employing a wireless pump

ABSTRACT

Systems, methods, and dressings for providing reduced pressure to a tissue site on a patient are presented that involve wirelessly providing power to a reduced-pressure pump. In one instance, a RFID antenna is used to power a reduced-pressure pump that is fluidly coupled by a conduit to a reduced-pressure dressing. In another instance, a reduced-pressure dressing incorporates a micro-pump and a RFID antenna that is used to power the micro-pump. Other systems, methods, and devices are presented.

RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 13/183,136, filed Jul. 14, 2011, which claims thebenefit, under 35 USC §119(e), of the filing of U.S. Provisional PatentApplication Ser. No. 61/407,194, entitled “System and Methods ForElectrically Detecting The Presence of Exudate In Reduced-PressureDressings,” filed 27 Oct. 2010, which is incorporated herein byreference for all purposes [VAC.0975PRO1]; U.S. Provisional PatentApplication Ser. No. 61/418,730, entitled “Systems and Methods forElectrically Detecting the Presence of Exudate in Dressings,” filed 1Dec. 2010, which is incorporated herein by reference for all purposes[VAC.0975PRO2]; U.S. Provisional Patent Application Ser. No. 61/445,383,entitled “Interactive, Wireless Reduced-Pressure Dressings, Methods, andSystems,” filed 22 Feb. 2011, which is incorporated herein by referencefor all purposes [VAC.0999PRO]; and U.S. Provisional Patent ApplicationSer. No. 61/445,338, entitled “Reduced-Pressure Systems, Dressings, andMethods Employing a Wireless Pump,” filed 22 Feb. 2011, which isincorporated herein by reference for all purposes [VAC.1000PRO].

FIELD

The present disclosure relates generally to medical treatment systemsand, more particularly, but not by way of limitation, to systems,dressings, and methods that involve wirelessly providing power to a pumpthat applies reduced pressure to a tissue site.

BACKGROUND

Clinical studies and practice have shown that providing a reducedpressure in proximity to a tissue site augments and accelerates thegrowth of new tissue at the tissue site. The applications of thisphenomenon are numerous, but application of reduced pressure has beenparticularly successful in treating wounds. This treatment (frequentlyreferred to in the medical community as “negative pressure woundtherapy,” “reduced pressure therapy,” or “vacuum therapy”) provides anumber of benefits, which may include faster healing and increasedformulation of granulation tissue. Typically, when applied to openwounds, reduced pressure is applied to tissue through a porous pad orother manifold device. The porous pad distributes reduced pressure tothe tissue and channels fluids that are drawn from the tissue. Reducedpressure may also be used to remove fluids from a body cavity, such asan abdominal cavity.

SUMMARY

According to an illustrative embodiment, a system for treating a tissuesite with reduced pressure includes a reduced-pressure dressing fordisposing proximate to the tissue site and a wireless, reduced-pressurepump fluidly coupled to the reduced-pressure dressing. The wireless,reduced-pressure pump includes a Radio Frequency Identification (RFID)antenna, a first processor coupled to the RFID antenna, a micro-pumpdevice coupled to the processor for receiving power and developingreduced pressure, a first pump-sealing member, a fluid reservoir, and asecond pump-sealing member. The first pump-sealing member and secondpump sealing are at least partially coupled to form a pump pouch inwhich the micro-pump is disposed. The system further includes a baseunit having a RFID reader. The RFID reader is configured to providepower to the RFID antenna such that the micro-pump is powered.

According to another illustrative embodiment, a method of manufacturinga system for treating a tissue site on a patient with reduced pressureincludes providing a reduced-pressure dressing for disposing proximateto the tissue site and providing a wireless, reduced-pressure pump. Thewireless, reduced-pressure pump includes a RFID antenna, a firstprocessor coupled to the RFID antenna, a micro-pump device coupled tothe first processor for receiving power and developing a reducedpressure, a first pump-sealing member, a fluid reservoir, and a secondpump-sealing member. The first pump-sealing member and second pumpsealing are at least partially coupled to form a pump pouch in which themicro-pump is disposed. The method may further include providing areduced-pressure delivery conduit for fluidly coupling the wireless,reduced-pressure pump to the reduced-pressure dressing. The methodfurther includes providing a base unit having a RFID reader. The RFIDreader is configured to provide power to the RFID antenna such that themicro-pump is powered.

According to another illustrative embodiment, a method for treating atissue site on a patient with reduced pressure includes placing areduced-pressure dressing proximate to the tissue site and providing awireless, reduced-pressure pump. The wireless, reduced-pressure pumpincludes a RFID antenna, a first processor coupled to the RFID antenna,a micro-pump device coupled to the processor for receiving power anddeveloping reduced pressure, a first pump-sealing member, a fluidreservoir, and a second pump-sealing member. The first pump-sealingmember and second pump sealing are at least partially coupled to form apump pouch in which the micro-pump is disposed. The method furtherincludes fluidly coupling the wireless, reduced-pressure pump to thereduced-pressure dressing, providing a base unit having a RFID readerand a second processor, and activating the base unit whereby the RFIDreader and second processor transmit an activation signal to thewireless, reduced-pressure pump to activate the wireless,reduced-pressure pump.

According to another illustrative embodiment, a reduced-pressure systemfor treating a tissue site with reduced pressure includes areduced-pressure dressing. The reduced-pressure dressing includes afirst distribution manifold for placing proximate to the tissue site, anabsorbent layer for receiving and retaining fluids from the firstdistribution manifold, a RFID antenna, a first processor coupled to theRFID antenna, and a micro-pump coupled to the first processor forreceiving power therefrom and developing reduced pressure. Themicro-pump has an inlet and an exhaust outlet. The system also includesa first sealing member for forming a sealed space over the tissue siteand the micro-pump, and a vent fluidly coupling the exhaust outlet ofthe micro-pump to an exterior. The system further includes a base unitthat includes a RFID reader. The base unit is operable to supply a pumpsignal to the reduced-pressure dressing to energize the micro-pump.

According to another illustrative embodiment, a method for treating atissue site on a patient with reduced pressure includes disposing awireless, reduced-pressure dressing proximate to the tissue site. Thewireless, reduced-pressure dressing includes a first distributionmanifold for placing proximate to the tissue site, an absorbent layerfor receiving and retaining fluids from the first distribution manifold,a RFID antenna, a first processor coupled to the RFID antenna, amicro-pump coupled to the first processor for receiving power therefromand developing reduced pressure. The micro-pump has an inlet and anexhaust outlet, a first sealing member for forming a sealed space overthe tissue site and the micro-pump, and a vent fluidly coupling theexhaust outlet of the micro-pump to an exterior. The method furtherincludes providing a base unit comprising a RFID reader. The base unitis operable to supply a pump signal to the wireless, reduced-pressuredressing to energize the micro-pump. The method also includes activatingthe base unit to deliver the pump signal to the wireless,reduced-pressure dressing.

Other features and advantages of the illustrative embodiments willbecome apparent with reference to the drawings and detailed descriptionthat follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram, with a portion shown in cross section, ofan illustrative embodiment of a system for treating a tissue site withreduced pressure;

FIG. 2 is a schematic, exploded, perspective view of an illustrativeembodiment of a wireless, reduced-pressure pump used as part of thesystem of FIG. 1;

FIG. 3 is a schematic diagram, with a portion shown in cross section, ofthe system of FIG. 1 presenting additional aspects and somealternatives;

FIG. 4 is a schematic, partial cross-sectional view of an illustrativeembodiment of a wireless, reduced-pressure pump;

FIG. 5 is a schematic, cross section of one illustrative embodiment of amicro-pump device for use as part of a system for treating a tissue sitewith reduced pressure such as in FIG. 1;

FIG. 6 is a schematic, perspective view of an illustrative embodiment ofa wireless, reduced-pressure pump;

FIG. 7 is a schematic, cross section of another illustrative embodimentof a wireless, reduced-pressure pump;

FIG. 8 is a schematic, perspective view of the wireless,reduced-pressure pump of FIG. 7;

FIG. 9 is a schematic diagram, with a portion shown in perspective view,of an illustrative embodiment of a reduced-pressure system for treatinga tissue site with reduced pressure;

FIG. 10 is a schematic, cross section of the reduced-pressure dressingshown in FIG. 9 taken along line 10-10;

FIG. 11 is a schematic, exploded, perspective view of thereduced-pressure dressing of FIGS. 9-10;

FIG. 12 is a schematic, cross section of an illustrative embodiment of asystem for treating a tissue site with reduced pressure; and

FIG. 13 is a schematic, exploded, perspective view of anotherillustrative embodiment of a reduced-pressure dressing.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the following detailed description of the illustrative, non-limitingembodiments, reference is made to the accompanying drawings that form apart hereof. These illustrative embodiments are described in sufficientdetail to enable those skilled in the art to practice the invention, andit is understood that other embodiments may be utilized and that logicalstructural, mechanical, electrical, and chemical changes may be madewithout departing from the spirit or scope of the invention. To avoiddetail not necessary to enable those skilled in the art to practice theembodiments described herein, the description may omit certaininformation known to those skilled in the art. The following detaileddescription is not to be taken in a limiting sense, and the scope of theillustrative embodiments is defined only by the appended claims.

The illustrative embodiments herein involve using Radio FrequencyIdentification (RFID) or an enhanced type of Radio FrequencyIdentification (RFID) technology to energize a micro-pump device in areduced-pressure dressing. RFID traditionally uses a RFID tag or labelthat is on a target and a RFID reader that energizes and reads signalsfrom the RFID tag. One common example is a toll tag. Most RFID tagsinclude an integrated circuit for storing and processing information, amodulator, and demodulator. RFID tags can be passive tags, active RFIDtags, and battery-assisted passive tags. Generally, passive tags use nobattery and do not transmit information unless they are energized by aRFID reader. Active tags have an on-board battery and can transmitautonomously (i.e., without being energized by a RFID reader).Battery-assisted passive tags typically have a small battery on-boardthat is activated in the presence of a RFID reader. To enhance the RFIDtag, a microcontroller and sensor may be incorporated into thereduced-pressure dressing. The RFID tag, a microcontroller and sensorallow sensing and optional computational functions. Moreover, the RFIDtag and microcontroller partially or entirely power a micro-pump.

In one illustrative embodiment, the enhanced RFID technology is aWireless Identification and Sensing Platform (WISP) device. WISPsinvolve powering and reading a WISP device, analogous to a RFID tag (orlabel), with a RFID reader. The WISP device harvests the power from theRFID reader's emitted radio signals and performs sensing functions (andoptionally performs computational functions). The WISP device transmitsa radio signal with information to the RFID reader. The WISP devicereceives power from the RFID reader. The WISP device has a tag orantenna that harvests energy and a microcontroller (or processor) thatcan perform a variety of tasks, such as sampling sensors. The WISPdevice reports data to the RFID reader. In one illustrative embodiment,the WISP device includes an integrated circuit with power harvestingcircuitry, demodulator, modulator, microcontroller, sensors, and mayinclude one or more capacitors for storing energy. A form of WISPtechnology has been developed by Intel Research Seattle. RFID devices asused herein also include WISP devices.

Referring now to the drawings and initially to FIGS. 1-5, anillustrative embodiment of a system 100 for treating a tissue site 102,e.g., a wound 104 or a cavity, with reduced pressure is presented. Thesystem 100 includes a reduced-pressure dressing 106 for disposingproximate to the tissue site 102; a wireless, reduced-pressure pump 108fluidly coupled to the reduced-pressure dressing 106; and a base unit110 having a RFID reader 112. The wireless, reduced-pressure pump 108includes a first RFID antenna 114 and a micro-pump device 116. The RFIDreader 112 is configured to provide and transmit a pump signal thatprovides power to the first RFID antenna 114. The pump signal receivedby the first RFID antenna 114 powers the micro-pump device 116. Remotelypowering the micro-pump device 116 provides a number of potentialbenefits. The benefits may include ease of application. In addition, thewireless, reduced-pressure pump 108 may be a self-contained, disposableunit. It should be noted that some variation is shown between figures inorder to show some of the potential variations in the illustrativesystem 100.

The system 100 may be used with various different types of tissue sites102. The tissue site 102 may be the bodily tissue of any human, animal,or other organism, including bone tissue, adipose tissue, muscle tissue,dermal tissue, vascular tissue, connective tissue, cartilage, tendons,ligaments, body cavity or any other tissue. Treatment of the tissue site102 may include removal of fluids, e.g., exudate or ascites.

The wireless, reduced-pressure pump 108 includes the first RFID antenna114 that is coupled to a first processor 118 by electrical leads 119.The first processor 118 is coupled to the micro-pump device 116, ormicro-pump, for receiving power. The first processor 118 may beincorporated into the micro-pump device 116. The first processor 118 andmicro-pump device 116 may be located within a pump pouch 120.

The pump pouch 120 may be formed by coupling a first pump-sealing member122 to a second pump-sealing member 124. The pump pouch 120 may also beformed by other techniques such as casting the pump pouch 120 from apolymer. At least a portion of the pump pouch 120 comprises a fluidreservoir 126 for receiving and retaining fluids 127 from the tissuesite 102. The micro-pump device 116 may be a piezoelectric pump, aperistaltic pump, or other small pump that produces reduced pressurewith minimal power requirements. The first processor 118 is operable toreceive a pressure message signal from a pressure sensing device 138. Inresponse to receiving the pressure message signal, the first processor118 produces a control signal to activate or deactivate the micro-pumpdevice 116. The pressure sensing device 138 may be a transducer or maybe a simple switch that is activated if sufficient reduced pressure ispresent.

Referring primarily to FIG. 3, the base unit 110 includes a secondprocessor 128 coupled to the RFID reader 112. A control panel 130 (e.g.,a user interface), a first display 132 and a power source 134 (e.g., abattery or electrical connection) may also be coupled to the secondprocessor 128. The base unit 110 may include a base housing 136. Thesecond processor 128 and RFID reader 112 are configured to transmit asignal 137, e.g., a pump signal or a pressure inquiry signal, to thefirst RFID antenna 114.

The first RFID antenna 114 of the reduced-pressure pump 108 is coupledby electrical leads 119 or a wireless coupling to the first processor118. The first processor 118 is coupled to the micro-pump device 116 toprovide power and control the micro-pump device 116. A first powersource 140 may be included to provide additional power to the firstprocessor 118. A pressure sensing device 138 may be coupled to the firstprocessor 118. The pressure sensing device 138 is fluidly coupled to andsenses pressure in a pressure sensing lumen 166 (or vent passageway 174or interface distribution manifold 150). The micro-pump device 116 isfluidly coupled to a fluid reservoir 126. The fluid reservoir 126receives and retains the fluids 127 from a reduced-pressure lumen 164 orfrom the interface distribution manifold 150.

The pump signal transmitted by the base unit 110 is received by thefirst RFID antenna 114 and energizes the micro-pump device 116 toproduce reduced pressure. The pressure inquiry signal is transmitted tothe first processor 118 of the wireless, reduced-pressure pump 108 bythe second processor 128 and RFID reader 112. In response, the firstprocessor 118 and pressure sensing device 138 of the wireless,reduced-pressure pump 108 transmit a pressure message signal indicativeof the pressure experienced at the reduced-pressure dressing 106 to thebase unit 110.

The second processor 128 is configured to receive the pressure messagesignal from the wireless, reduced-pressure pump 108 and prepare acontrol signal. The second processor 128 and RFID reader 112 areconfigured to transmit the control signal to the wireless,reduced-pressure pump 108 to activate or deactivate the micro-pumpdevice 116. In another illustrative embodiment, as previously mentioned,the first processor 118 is operable to receive a pressure message signalfrom the pressure sensing device 138 and to produce a control signal toactivate or deactivate the micro-pump device 116.

Referring now primarily to FIGS. 2 and 4, the wireless, reduced-pressurepump 108 generates reduced pressure that is delivered to the tissue site102. The wireless, reduced-pressure pump 108 receives and retains fluidsfrom the tissue site 102. Reduced pressure generally refers to apressure less than the ambient pressure at a tissue site that is beingsubjected to treatment. In most cases, this reduced pressure will beless than the atmospheric pressure at which the patient is located.Alternatively, the reduced pressure may be less than a hydrostaticpressure at the tissue site. Unless otherwise indicated, values ofpressure stated herein are gauge pressures. The reduced pressuredelivered may be constant or varied (patterned or random) and may bedelivered continuously or intermittently. Consistent with the useherein, unless otherwise indicated, an increase in reduced pressure orvacuum pressure typically refers to a relative reduction in absolutepressure.

The wireless, reduced-pressure pump 108 provides the reduced pressurefor the system 100. The wireless, reduced-pressure pump 108 may includea first distribution manifold 142, a diverter layer 144, and anabsorbent layer 146. A vent 176 is used to fluidly couple an exhaustfrom the micro-pump device 116 to an exterior of the wireless,reduced-pressure pump 108. The first distribution manifold 142 functionsto distribute reduced pressure generated by the micro-pump device 116.An air/liquid separator 143, e.g., a hydrophobic filter, may be placedbetween the micro-pump device 116 and the first distribution manifold142 to prevent liquid from entering the micro-pump device 116. Theabsorbent layer 146 functions to receive and retain fluids from thetissue site 102. The absorbent layer 146 may be made from any materialcapable of absorbing liquid, such as exudate from the tissue site 102.

The absorbent layer 146 may be made from super absorbent fibers. Thesuper absorbent fibers may retain or bond to the liquid in conjunctionwith a physical or chemical change to the fibers. In one non-limitingexample, the super absorbent fiber may include the Super Absorbent Fiber(SAF) material from Technical Absorbents, Ltd. of Grimsby, UnitedKingdom. The absorbent layer 146 may be a sheet or mat of fibrousmaterial in which the fibers absorb liquid from the tissue site 102. Thestructure of the absorbent layer 146 that contains the fibers may beeither woven or non-woven. The fibers in the absorbent layer 146 may gelupon contact with the liquid, thereby trapping the liquid. Spaces orvoids between the fibers may allow reduced pressure that is applied tothe absorbent layer 146 to be transferred within and through theabsorbent layer 146. In one illustrative embodiment, the fiber densityof the fibers in the absorbent layer 146 may be approximately 1.4 gramsper millimeter.

The diverter layer 144 is disposed adjacent to the absorbent layer 146and the first distribution manifold 142. The diverter layer 144 isformed from a liquid impermeable material but contains a plurality ofapertures 145. The plurality of apertures 145 allow reduced pressurefrom the micro-pump device 116 to be transmitted through the diverterlayer 144 at desired locations. The diverter layer 144 helps control thepattern of reduced pressure as applied to the absorbent layer 146. Thereduced pressure is distributed to the diverter layer 144 by the firstdistribution manifold 142. The apertures 145 may be arranged in apattern for applying the reduced pressure to portions of the absorbentlayer 146 to enhance the capability of the absorbent layer 146 tocontinue transferring reduced pressure to the tissue site 102 as theabsorbent layer 146 absorbs more fluid from the tissue site 102.

The plurality of apertures 145 may be positioned in a pattern around aperipheral portion of the diverter layer 144 away from the center of thediverter layer 144 such that the reduced pressure is applied to theabsorbent layer 146 away from a center region of the absorbent layer146. The diverter layer 144 acts in conjunction with the firstdistribution manifold 142 to ensure that the absorption capabilities andabsorption efficiency of the absorbent layer 146 are increased relativeto an absorbent layer 146 that is not used in conjunction with adiverter layer 144. By providing better distribution of liquidthroughout the absorbent layer 146, the diverter layer 144 alsoincreases the effective capacity and treatment time of the wireless,reduced-pressure pump 108.

The diverter layer 144 may be made from any material that enhances thereduced pressure transmission and storage capabilities of an adjacentabsorbent layer. For example, the diverter layer 144 may be made from amaterial that is substantially impermeable to liquid and gas and thatdiverts the reduced pressure to pass through apertures 145.Alternatively or in addition, the material from which the diverter layer144 is made may have a predetermined moisture vapor transfer rate thatis consistent with gas permeability. In either example, the diverterlayer 144 may still include a pattern of apertures for transmitting agreater volume of liquid or gas than that permitted by a gas-permeablematerial not having apertures. It should be noted, however, thatpermeability of the diverter layer 144 to gas but not liquid may resultin increased transmission of reduced pressure through the dressing whilestill directing liquid flow around or near the perimeter of the diverterlayer 144.

The first distribution manifold 142, the diverter layer 144, and theabsorbent layer 146 may be disposed within the pump pouch 120. Thewireless, reduced-pressure pump 108 may also include the pressuresensing device 138, which is fluidly coupled to the reduced-pressuredressing 106 and in communication with the first processor 118 forsensing pressure. The reduced-pressure conduit 148 delivers fluids fromthe reduced-pressure dressing 106 to the wireless, reduced-pressure pump108. In one illustrative embodiment, the reduced-pressure conduit 148 isdisposed directly into the absorbent layer 146. In another illustrativeembodiment, an interface (not shown) fluidly couples thereduced-pressure conduit 148 and the absorbent layer 146.

Referring now primarily to FIGS. 1 and 3, the reduced-pressure dressing106 is disposed against the tissue site 102. The tissue site 102 may be,for example, the wound 104 through epidermis 156 and into subcutaneoustissue 158 or any other tissue site. The reduced-pressure dressing 106may be any device for providing reduced pressure to the tissue site 102and for receiving fluids from the tissue site 102. For example, thereduced-pressure dressing 106 may be formed with a foam member, astructure with a plurality of defined channels, a suction tube, or otherdevice. In one illustrative embodiment, the reduced-pressure dressing106 may include the interface distribution manifold 150 for placingproximate to the tissue site 102, a dressing sealing member 152, and areduced-pressure interface 154.

A manifold is a substance or structure that is provided to assist inapplying reduced pressure to, delivering fluids to, or removing fluidsfrom a tissue site 102. The interface distribution manifold 150typically includes a plurality of flow channels or pathways thatdistribute fluids provided to and removed from the tissue site 102around the interface distribution manifold 150. In one illustrativeembodiment, the flow channels or pathways are interconnected to improvedistribution of fluids provided or removed from the tissue site 102. Theinterface distribution manifold 150 may be a biocompatible material thatis capable of being placed in contact with the tissue site 102 anddistributing reduced pressure to the tissue site 102. Examples ofinterface distribution manifolds may include without limitation thefollowing: devices that have structural elements arranged to form flowchannels, e.g., cellular foam, open-cell foam, porous tissuecollections, liquids, gels, and foams that include, or cure to include,flow channels; foam; gauze; felted mat; or any other material suited toa particular biological application.

In one embodiment, the interface distribution manifold 150 is a porousfoam and includes a plurality of interconnected cells or pores that actas flow channels. The porous foam may be a polyurethane, open-cell,reticulated foam such as GranuFoam® material available from KineticConcepts, Incorporated of San Antonio, Tex. In some situations, theinterface distribution manifold 150 may also be used to distributefluids such as medications, antibacterials, growth factors, and varioussolutions to the tissue site 102. Other layers may be included in or onthe interface distribution manifold 150, such as absorptive materials,wicking materials, hydrophobic materials, and hydrophilic materials.

In one illustrative embodiment, the interface distribution manifold 150in whole or in part may be constructed from bioresorbable materials thatmay remain in a patient's body following use of the reduced-pressuredressing 106. Suitable bioresorbable materials may include, withoutlimitation, a polymeric blend of polylactic acid (PLA) and polyglycolicacid (PGA). The polymeric blend may also include without limitationpolycarbonates, polyfumarates, and capralactones. The interfacedistribution manifold 150 may further serve as a scaffold for newcell-growth, or a scaffold material may be used in conjunction with theinterface distribution manifold 150 to promote cell-growth. A scaffoldis a substance or structure used to enhance or promote the growth ofcells or formation of tissue, such as a three-dimensional porousstructure that provides a template for cell growth. Illustrativeexamples of scaffold materials include calcium phosphate, collagen,PLA/PGA, coral hydroxy apatites, carbonates, or processed allograftmaterials.

The interface distribution manifold 150 is covered by a dressing sealingmember 152. The dressing sealing member 152 may be any material thatprovides a fluid seal. A fluid seal is a seal adequate to maintainreduced pressure at a desired site given the particular reduced-pressuresource or subsystem involved. The dressing sealing member 152 may, forexample, be an impermeable or semi-permeable, elastomeric material.Elastomeric materials have the properties of an elastomer. It generallyrefers to a polymeric material that has rubber-like properties. Morespecifically, most elastomers have ultimate elongations greater than100% and a significant amount of resilience. The resilience of amaterial refers to the material's ability to recover from an elasticdeformation. Examples of elastomers include, but are not limited to,natural rubbers, polyisoprene, styrene butadiene rubber, chloroprenerubber, polybutadiene, nitrile rubber, butyl rubber, ethylene propylenerubber, ethylene propylene diene monomer, chlorosulfonated polyethylene,polysulfide rubber, polyurethane (PU), EVA film, co-polyester, andsilicones. Additional, specific examples of dressing sealing membermaterials include a silicone drape, 3M Tegaderm® drape, polyurethane(PU) drape such as one available from Avery Dennison Corporation ofPasadena, Calif. The dressing sealing member 152 forms a sealed space160 over the tissue site 102, which may or may contain the micro-pumpdevice 116.

An attachment device 162 may be used to retain the dressing sealingmember 152 against the patient's epidermis 156 or another layer, such asa gasket or additional sealing member. The attachment device 162 maytake numerous forms. For example, the attachment device 162 may be amedically acceptable, pressure-sensitive adhesive that extends about aperiphery or all of the dressing sealing member 152 or covers at least apotion of the dressing sealing member 152 on a patient-facing side overthe epidermis 156.

The reduced-pressure interface 154 may be used to provide fluidcommunication between the reduced-pressure conduit 148 and the sealedspace 160 of the reduced-pressure dressing 106. The reduced pressure maybe delivered through the reduced-pressure conduit 148 to thereduced-pressure interface 154 and then to the sealed space 160. In oneillustrative embodiment, the reduced-pressure interface 154 is aT.R.A.C.® Pad or Sensa T.R.A.C.® Pad available from KCI of San Antonio,Tex. The reduced-pressure conduit 148 may include the reduced-pressurelumen 164 and the pressure sensing lumen 166 formed as an integralconduit as shown in FIG. 1 or separately as shown in FIG. 3.

In one illustrative embodiment shown in FIG. 1, pressure sensingcapability may be added to the reduced-pressure dressing 106 to functionin addition to or in lieu of pressure sensing device 138. Thereduced-pressure dressing 106 may include a second RFID antenna 168, athird processor 170, and a second pressure sensing device 172. The thirdprocessor 170 is coupled to the second RFID antenna 168 and to thesecond pressure sensing device 172. A vent passageway 174 provides fluidcommunication between the sealed space 160 and the second pressuresensing device 172. The third processor 170 and the second pressuresensing device 172 are operable to receive a pressure inquiry signalfrom the base unit 110 and respond with a pressure message signalindicative of the pressure in the sealed space 160.

In one illustrative embodiment, the wireless, reduced-pressure pump 108is a wireless and passive (i.e., no battery) device. As such, thewireless, reduced-pressure pump 108 has no source of power other thanpower delivered through the first RFID antenna 114. In some embodiments,the wireless, reduced-pressure pump 108 may contain a capacitor forstoring electrical energy. In another illustrative embodiment, the firstpower source 140 as shown in FIG. 3 may be provided to augment the powerdelivered through the first RFID antenna 114 or to operate themicro-pump device 116. The first power source 140 may be recharged bypower from the first RFID antenna 114.

The micro-pump device 116 may take numerous forms such as apiezoelectric pump, peristaltic pump, or other miniaturized pump.Referring now primarily to FIG. 5, an illustrative embodiment of amicro-pump device 116 that is suitable for use as an aspect of thewireless, reduced-pressure pump 108 is presented. The micro-pump device116 includes a cavity 178 that is defined by a first end wall 180, asecond end wall 182, and an annular side wall 184. The cavity 178 may besubstantially circular in shape, but other shapes are possible, such aselliptical. In one illustrative embodiment, the cavity 178 may holdabout 10 ml of fluid or may hold more or less.

The cavity 178 is provided with a nodal inlet 186, which may be valvedor unvalved. The cavity 178 may also have a valved outlet 190. The firstend wall 180 may be a disc 192. On the disc 192 is an actuator 194, suchas a piezoelectric disc, magnetostrictive device, or solenoid actuateddevice. The actuator 194 is electrically coupled to a drive circuit,which is controlled by the processor. The drive circuit will apply analternating electrical signal to the actuator 194 to induce anoscillation in the disc 192. The frequency of the oscillation can beadjusted to match the natural frequency of the chamber. Thepiezoelectric disc may be less than 1 mm in thickness and may be tunedto operate at more than 500 Hz, more than 10 kHz, or even higher than 20kHz. Upon activation, the actuator 194 may vibrate in a directionsubstantially perpendicular to the plane of the cavity 178 as shown,thereby generating radial pressure oscillations within the fluid in thecavity 178. One or more micro-pump devices 116 may be used in parallelor series.

In one illustrative embodiment, the micro-pump device 116 has a fluid inthe cavity 178 and has a substantially cylindrical shape that is boundedby the first end wall 180, second end wall 182, and side wall 184. Atleast two apertures, e.g., inlet 186 and outlet 190, are formed throughthe walls 180, 182, 184 forming the cavity 178. The cavity 178 has aradius, r, and a height, h, and r/h>1.2 and h²/r>4×10⁻¹⁰ m. The actuator194, which is a piezoelectric disc, creates an oscillatory motion of oneof the end walls 180, 182 in a direction that is substantiallyperpendicular to the plane of the first end wall 180 and second end wall182. Axial oscillations of the end walls 180, 182 drive radialoscillations of fluid pressure in the cavity 178 and allow for pumpingthat creates reduced pressure. The micro-pump device 116 is like anacoustic pump in that an acoustic resonance is set up within the cavity178. The inlet 186 is used to pull fluids, and the outlet 190 is coupledto a vent, e.g., the vent 176 in FIG. 4, to discharge to an exterior.Other micro-pump devices may be used. The micro-pump device 116 may bethe type of micro-pump shown in United States Patent Publication2009/0240185 (application Ser. No. 12/398,904; filed 5 Mar. 2009),entitled, “Dressing and Method for Applying Reduced Pressure To andCollecting And Storing Fluid from a Tissue Site,” which is incorporatedherein for all purposes.

Referring now primarily to FIGS. 1-3, according to one illustrativeembodiment, in operating the system 100, the reduced-pressure dressing106 is applied to the tissue site 102. In particular, the interfacedistribution manifold 150 is disposed proximate to the tissue site 102.Then the interface distribution manifold 150 and the tissue site 102 arecovered by the dressing sealing member 152 to create the sealed space160. The attachment device 162 on the patient-facing side of thedressing sealing member 152 may help provide a fluid seal against aportion of the patient's epidermis 156. If not already installed, thereduced-pressure interface 154 may be applied, such as for example bycutting a small aperture in the dressing sealing member 152 and securingthe reduced-pressure interface 154 over or through the aperture, orhole.

The wireless, reduced-pressure pump 108 is then provided and fluidlycoupled by the reduced-pressure conduit 148 to the reduced-pressureinterface 154. The wireless, reduced-pressure pump 108 is positionedsuch that the first RFID antenna 114 is placed within operating range ofthe base unit 110. In one illustrative embodiment, the first RFIDantenna 114 is placed within a few millimeters of the RFID reader 112 ofthe base unit 110. In another illustrative embodiment, the first RFIDantenna 114 may be placed as far away as ten meters from the RFID reader112. Any distance within the given range may be readily used.

The base unit 110 is then activated by the user. The base unit 110transmits a pump signal 137 to the wireless, reduced-pressure pump 108.The pump signal is received by the first RFID antenna 114, and theenergy of the pump signal is delivered to the first processor 118. Thefirst processor 118 provides energy to the micro-pump device 116. Themicro-pump 116 creates reduced pressure that is delivered into the fluidreservoir 126 that is fluidly coupled to the reduced-pressure conduit148. Thus, the reduced pressure is delivered to the reduced-pressuredressing 106 through the reduced-pressure conduit 148. Fluids from thetissue site 102 flow through the interface distribution manifold 150,reduced-pressure interface 154, and reduced-pressure conduit 148 intothe fluid reservoir 126.

The pressure at the tissue site 102 may be monitored directly orindirectly using a pressure sensing device, such as pressure sensingdevice 138 of FIG. 3 or second pressure sensing device 172 of FIG. 1. Inthe first illustrative example, the second processor 128 and the RFIDreader 112 of the base unit 110 may, separate from the pump signal orwith the pump signal, transmit a pressure inquiry signal to thewireless, reduced-pressure pump 108. In response to the pressure inquirysignal, the first processor 118 and pressure sensing device 138 mayprepare a pressure message signal to communicate a measurement of thepressure at the tissue site. Then, the pressure message signal may beused for further processing by the first processor 118 to develop a pumpcontrol signal for activating or deactivating the micro-pump 116 as maybe needed. Alternatively or in addition, the first processor 118 maytransmit the pressure message signal via the first RFID antenna 114 tothe RFID reader 112. After arriving at the RFID reader 112, the pressuremessage signal is delivered to the second processor 128. Using thepressure message signal, the second processor 128 may prepare a pumpcontrol signal that is transmitted by the RFID reader 112 to thewireless, reduced-pressure pump 108 to deactivate or activate themicro-pump 116 as needed.

If, after providing an adequate interval, the pressure remains outsideof a desired operating range, an alarm signal is created by the baseunit 110 or by the wireless, reduced-pressure pump 108. The alarm may bea separate audible device, visual alarm, or the micro-pump 116 mayfunction at a different frequency range, e.g., lower, to make an audiblenoise for the alarm.

With the second illustrative approach, the reduced-pressure dressing 106includes the second RFID antenna 168 that is coupled to the thirdprocessor 170, which is coupled to the second pressure sensing device172. The second pressure sensing device 172 experiences the pressurewithin the sealed space 160 via the vent passageway 174. The base unit110 transmits a pressure inquiry signal to the second RFID antenna 168.In response, the second pressure sensing device 172 and third processor170 produce a pressure message signal that is transmitted by the secondRFID antenna 168 to the base unit 110. As before, the base unit 110 thenproduces a pump control signal that is transmitted to the wireless,reduced-pressure pump 108 to activate or deactivate the micro-pump 116.Alternatively, the third processor 170 may evaluate the pressure andprepare a pump control signal as part of a feedback or control loop.

Referring now primarily to FIGS. 4 and 6, an illustrative embodiment ofa wireless, reduced-pressure pump 108 is presented. In this illustrativeembodiment, the wireless, reduced-pressure pump 108 may be aself-contained, disposable pouch design that may be removably secured toa base unit 110 on a pole 196. As previously presented, a pump pouch 120is formed with a first pump-sealing member 122 and a second pump-sealingmember 124. The perimeter of the pump pouch 120 may include a firstflange 123 and a second flange 125. The pump pouch 120 may be divided orpartitioned into numerous compartments if desired. For example, acompartment (not explicitly shown) may be formed that has the micro-pump116 within the compartment and another compartment may formed thatcontains the absorbent layer 146.

The flanges 123, 125 on the illustrative embodiment of the pump pouch120 may be formed by welding, bonding or otherwise attaching portions ofthe first pump-sealing member 122 and second pump-sealing member 124.The first flange 123 may include one or more apertures 129 for receivingone or more posts 198. The posts 198 secure the pump pouch 120 adjacentto the base unit 110. The reduced-pressure conduit 148 may enter throughan aperture 149 in the second flange 125 that provides a sealed,interference fit or has a coupling that provides a sealed connection.Other connections may be used.

The first RFID antenna 114 may be placed closest to the base unit 110such that the first RFID antenna 114 is immediately adjacent to RFIDreader 112 of the base unit 110 as shown best in FIG. 4. In onenon-limiting example, the first RFID antenna 114 is positioned twomillimeters or one millimeter (1 mm) or less from the RFID reader 112.The RFID reader 112 and the first RFID antenna 114 may be substantiallymatched and aligned. In another illustrative embodiment, the wireless,reduced-pressure pump 108 may be attached to a post 198 with the firstRFID antenna 114 facing outward towards a remotely located base unit 110as suggested in FIG. 1. For example, the base unit 110 may be located ata central hub area where the wireless, reduced-pressure pump 108 ismonitored and powered using the base unit 110, which may be as far awayas ten meters or more.

Referring now primarily to FIG. 6, the base unit 110 may include thecontrol panel 130 and one or more displays 132. The base unit 110 mayinclude a base housing or base body 136. The base housing or body 136may include a shelf portion 199 that may provide physical support to aportion of the wireless, reduced-pressure pump 108 when the wireless,reduced-pressure pump 108 fills with fluids from the tissue site 102. Inthis regard, it should be noted that the wireless, reduced-pressure pump108 shown in FIG. 6 is shown before use. With the embodiments of FIGS. 4and 6, when the wireless, reduced-pressure pump 108 has reached itscapacity for holding fluids, the micro-pump 116 may be deactivated andthe user may dispose of the entire wireless, reduced-pressure pump 108.

Referring now primarily to FIGS. 7 and 8, another illustrativeembodiment of a wireless, reduced-pressure pump 200 is presented. Thewireless, reduced-pressure pump 200 may be used as part of a system fortreating a tissue site, e.g., the system of FIG. 1. The wireless,reduced-pressure pump 200 includes a plurality of wall members 202 thatform a first chamber 204 and a second chamber 206. One of the pluralityof wall members 202 is a partitioning wall 208 that separates the firstchamber 204 from the second chamber 206. A micro-pump 210, which isanalogous to the micro-pump 116 of the previous figures, may be disposedwithin the first chamber 204. The micro-pump 116 is configured such thatthe inlet 212 that receives fluid (or said another way, dischargesreduced pressure) is fluidly coupled to the second chamber 206. Themicro-pump 210 has an outlet or vent 214 that is fluidly coupled to thefirst chamber 204. The micro-pump 210 vents positive pressure throughoutlet or vent 214 into the first chamber 204.

A portion of one of the plurality of wall members 202 that forms thefirst chamber 204 contains an aperture 216. An optional relief valve 218is coupled to the aperture 216. The relief valve 218 is configured toallow pressure within the first chamber 204 to vent to an exterior ofthe wireless, reduced-pressure pump 200 when the pressure exceeds afirst threshold pressure. At least a portion of the plurality of wallmembers 202 that make up the second chamber 206 includes an inflatablesupport member and typically a plurality of inflatable support members220. While a plurality of inflatable support members 220 are presented,it should be understood that a single inflatable support member may beused create the second chamber 206.

The inflatable support members 220 are in fluid communication with thefirst chamber 204, such as through a plurality of apertures 222. Thus,the positive pressure within the first chamber 204 fills the pluralityof inflatable support members 220. As the plurality of inflatablesupport members 220 are filled with sufficient fluid, the plurality ofinflatable support members 220 gain relative rigidity that provides astructure that helps provide volume to the second chamber 206. Fluids223 from a tissue site are received through a reduced-pressure conduit224 into the volume of the second chamber 206. The wireless,reduced-pressure pump 200, which is shown in the shape of a pyramid, maybe formed to take other shapes, e.g., a box, a cylinder, or any othershape.

As with the previous illustrative embodiments, the micro-pump 210 may befully or partially powered by a pump signal delivered to a RFID antenna226. The RFID antenna 226 is coupled to a first processor 228. The firstprocessor 228 is electrically coupled to the micro-pump 210 by anelectrical lead 230, which may be contained in one of the plurality ofwall members 202 but is shown separately in FIG. 7. As shown in FIG. 8,a floor portion 232 of the plurality of wall members 202 may becontained within a platform member 234.

Referring now primarily to FIGS. 7 and 8, in operation according to oneillustrative embodiment, the reduced-pressure conduit 224 is coupled toa reduced-pressure dressing, such as reduced-pressure dressing 106 ofFIGS. 1 and 3. A base unit, e.g., base unit 110 of FIG. 1, is used totransmit a pump signal or a pump activation signal to the RFID antenna226 of the wireless, reduced-pressure pump 200. The pump signal receivedby the RFID antenna 226 is delivered to the first processor 228. Poweris delivered from the first processor 228 to the micro-pump 210 toenergize micro-pump 210. As the micro-pump 210 is energized, reducedpressure is delivered into the second chamber 206 and positive pressureis delivered to the first chamber 204. As pressure builds in the firstchamber 204, the pressure fills the plurality of inflatable supportmembers 220 such that the wireless, reduced-pressure pump 200 changesfrom a deflated state to an inflated state. A spacer member (not shown)may cover the inlet 212 to avoid a vapor lock during start up before theinflatable support members 220 fill.

Once the inflatable support members 220 are inflated, the maximum volumeis achieved for the second chamber 206. Meanwhile, the reduced pressurein the second chamber 206 is delivered to the reduced-pressure conduit224. Fluids 223 (including liquids) are introduced into the secondchamber 206.

While not explicitly shown, it should be understood that areduced-pressure sensing device, e.g., analogous to pressure sensingdevice 138 in FIG. 3, may be incorporated into a portion of the secondchamber 206 to measure pressure in the second chamber 206. Again, whilenot explicitly shown, it should be understood that a reduced-pressuresensing device, e.g., analogous to pressure sensing device 138 in FIG.3, may be included in the reduced-pressure pump 200. Thereduced-pressure conduit 224 may also have a pressure sensing lumen thatis fluidly coupled to the reduced-pressure sensing device for measuringpressure at a distribution manifold. In both examples, the pressuresensing device is coupled to the first processor 228 to develop apressure message signal. The pressure message signal may be supplied inresponse to a pressure inquiry signal from a base unit or self-generatedby the first processor 228. The first processor 228 may use the pressuremessage signal to develop a pump control signal that is delivered to themicro-pump 210. Alternatively, the pressure message signal may betransmitted to the base unit where a processor in the base unit maydevelop a pump control signal similar to the embodiments previouslypresented.

In an alternative embodiment, the wireless, reduced-pressure pumps 108,200 previously presented have, instead of having RFID antennas,electrical leads or sockets and plugs between the pumps and base. Theelectrical leads or sockets and plugs may readily plug into one anotherfor communicating power and signals.

Referring now primarily to FIGS. 9-11, an illustrative embodiment of areduced-pressure system 300 for treating a tissue site 302 with reducedpressure is presented. The reduced-pressure system 300 includes awireless, reduced-pressure dressing 304 and a base unit 306. The baseunit 306 may include a power connector 307. The wireless,reduced-pressure dressing 304 is a self-contained, disposable dressingthat receives power and control from the base unit 306. The base unit306 may be substantially adjacent to the wireless, reduced-pressuredressing 304, e.g., within one or two millimeters, or up to 10 meters ormore away or anywhere in between. In one embodiment, the micro-pump 316may be separate from an absorbent layer or absorbent member 310, suchthat after use, the micro-pump 316 may be readily separated. Themicro-pump 316 may then be reconditioned and reused.

The wireless, reduced-pressure dressing 304 includes an interfacedistribution manifold 308 that is placed proximate to the tissue site302. The wireless, reduced-pressure dressing 304 may also include anabsorbent layer 310, a RFID antenna 312, and a first processor 314. TheRFID antenna 312 is electrically coupled to the first processor 314. Thefirst processor 314 is electrically coupled to the micro-pump 316. Theinterface distribution manifold 308, absorbent layer 310, RFID antenna312, first processor 314, and micro-pump 316 may all be retained inplace and secured in a sealed space 318 by one or more sealing members,such as sealing member 320. Additional layers and components may beincluded in the wireless, reduced-pressure dressing 304.

The illustrative embodiment of FIGS. 9-11 includes additional layersand, components. The additional layers and components may be arranged indifferent orders. A sealing layer 322 is used to seal the wireless,reduced-pressure dressing 304 around the tissue site 302. The sealinglayer 322 is formed with an aperture 323 for providing fluidcommunication to the interface distribution manifold 308. A firstinternal distribution manifold 324 is positioned in fluid communicationwith the interface distribution manifold 308 and the tissue site 302.The absorbent layer 310 is positioned in fluid communication with thefirst internal distribution manifold 324, the interface distributionmanifold 308, and a tissue site 302. A diverter layer 326 is positionedadjacent to the absorbent layer 310. A second internal distributionmanifold 328 is positioned in fluid communication with the diverterlayer 326. The diverter layer 326 is formed with a plurality ofapertures 327 that may take numerous patterns and forms. The diverterlayer 326 is shown in this particular illustrative embodiment with aplurality of apertures 327 forming a square pattern. The square patternhas corner apertures that are larger than the other apertures. Aliquid-air separator 330 is positioned adjacent to the second internaldistribution manifold 328.

The micro-pump 316, RFID antenna 312, and first processor 314 may beadjacent to the liquid-air separator 330. A charcoal filter 332 or otherodor relieving device may be positioned over an outlet 334 of themicro-pump 316. The sealing member 320 is formed with an aperture 336that allows the outlet 334 of the micro-pump 316 to exhaust to anexterior of the wireless, reduced-pressure dressing 304. The outlet 334and aperture 336 together form a vent 338.

The micro-pump 316 may be a micro-pump that is small and light enoughsuch that the integrated wireless, reduced-pressure dressing 304 is ableto be maintained on the tissue site 302. Furthermore, the size andweight of the micro-pump 316 may be such that the integratedreduced-pressure dressing 304 does not pull or otherwise adverselyaffect the tissue site 302. In one illustrative embodiment, themicro-pump 316 may be a disk pump having a piezoelectric actuatorsimilar to that previously described. Reference is also made to thepumps shown in United States Patent Publication 2009/0087323 and UnitedStates Patent Publication 2009/0240185, which are hereby incorporated byreference for all purposes. In an alternative embodiment, the micro-pump316 may be a peristaltic pump that is used for pumping a variety offluids. It should be understood that alternative pump technologies maybe utilized and that rotary, linear, or other configurations of pumpsmay be utilized.

The micro-pump 316 creates sufficient reduced pressure to be therapeuticfor wound therapy. In one illustrative embodiment, the micro-pump 316has sufficient flow, reduced pressure, and operation lifecharacteristics to enable continuous application of reduced pressuretreatment. The flow may range between about 5-1000 ml/min and thereduced pressure may range between about −50 and −200 mm Hg (−6.6 to−26.6 kPa). It should be understood that alternative ranges may beutilized depending on the configuration of the integrated, wireless,reduced-pressure dressing 304, size of wound, or type of wound. In oneillustrative embodiment, multiple pumps may be positioned in a singledressing to deliver increased flow rates or vacuum levels as required.

The micro-pump 316 is disposed within the dressing to avoid conduits andexternal canisters for collection of wound exudate. The micro-pump 316includes the outlet 334 to release air or exhaust out of thereduced-pressure dressing 304. If the outlet 334 is used, the outlet 334is in fluid communication with, or may be positioned within, theaperture 336 of the sealing member 320. Alternatively, the sealingmember 320 may be sealed around an outlet port of the micro-pump 316such that gas from the micro-pump 316 is able to exhaust directlythrough the aperture 336. In the illustrative embodiment in FIGS. 9-11,the outlet 334 of the micro-pump 316 is oriented in a direction awayfrom the liquid-air separator 330 (or hydrophobic filter) to avoidadding air to the wireless, reduced-pressure dressing 304. The airexhausts through an aperture 336 in the sealing member 320, which mayinclude a one-way valve. Alternatively, the air or another gas could beexhausted through a gas-permeable portion of the sealing member 320 aslong as the ability of the sealing member 320 to maintain reducedpressure is not affected.

When the micro-pump 316 is a piezoelectric pump, the piezoelectricactuator associated with the micro-pump 316 may be driven at differentfrequencies to act as a buzzer or vibrating alert system at times. Thealert system may alert a user to an alarm condition. For example, thealarm condition may indicate the presence of a leak in the dressing, achange in reduced pressure as measured by a sensor, that the dressinghas absorbed a maximum capacity of liquid as may be indicated by anindicator, or that one or more layers are no longer manifolding reducedpressure efficiently.

Control electronics, may be physically or functionally incorporated aspart of the first processor 314. The control electronics may be utilizedto control operation of the micro-pump 316. The control electronics maybe analog or digital and be configured with a regulator to regulatespeed or duty cycle at which the micro-pump 316 operates. Furthermore,the control electronics may be configured with a controller thatreceives sense signals from sensors or switches, e.g., a pressuresensing device (see 340 in FIG. 12). The sensors may be disposedthroughout the wireless, reduced-pressure dressing 304 to senseparameters, such as pressure, temperature, moisture, chemistry, odor, orany other parameter that may be utilized in managing and controlling themicro-pump 316. The control electronics may include a computer processoror programmable gate array or other control device. It should beunderstood that the control electronics may include any form of digitalor analog components to perform the functions described herein. Thecontrol electronics may be or include the first processor 314.

The control electronics may be arranged to monitor and provide an alarmfor certain conditions, e.g., (i) low pressure, (ii) excessive leak,(iii) level of absorbent layer, and (iv) battery state (if included).Accordingly, the control electronics may include electronics thatmonitor each of the parameters and generate an alarm signal (e.g.,high-pitched beep, vibration, or light) using a speaker, vibrator, orillumination device, such as a light emitting diode (LED). Thus, thecontrol electronics may notify a medical professional, patient, orfamily member that a parameter is outside of a desired range. Forexample, if a pressure at the tissue site 302 is below a therapeuticlevel, a continuous tone may be generated. As another example, if theabsorbent layer 310 is saturated, then continuous beeps may begenerated. If the battery drops below a certain voltage level, then adifferent audible frequency may be generated or an LED may be activated.A variety of different alarm signals may be established to notify amedical professional to take a particular action.

The RFID antenna 312 is utilized to provide electric power to themicro-pump 316 and control electronics. A battery 342 may also be usedto provide stored energy to augment power from the RFID antenna 312. Thebattery 342 may be any size and shape and may be of any material, suchas polymer. The battery 342 may provide the entire needed power or aportion thereof. The battery 342 may be recharged by power from the RFIDantenna 312.

In one illustrative embodiment, the battery 342 may be configured with avoltage level sensor that is monitored by the control electronics, andthe control electronics may provide an alarm when a low power level isdetected. The battery 342 may be directly connected to the micro-pump316. Alternatively, the battery 342 may be connected to the controlelectronics or processor(s) that use power from the battery 342 to drivethe micro-pump 316. The control electronics may provide continuous,modulated power, such as a pulsewidth modulated (PWM) signal, to drivethe micro-pump 316.

The sealing layer 322 is adhered to or otherwise connected to thesealing member 320 that is used to drape or otherwise cover thecomponents of the reduced-pressure dressing 304. The sealing layer 322may include a medical-grade adhesive material or other sealing devicethat is strong enough to form a vacuum seal with epidermis around awound of a patient. The sealing layer 322 may be a band that has anaperture 323 that is slightly larger than the geometric parameters ofthe liquid-air separator 330 or other layer so that the sealing member320 contacts epidermis around the tissue site 302 of the patient. Thesealing member 320 is impermeable to fluids, such as air and liquids.

In another illustrative embodiment, the sealing member 320 may beadhered to the diverter layer 326 and the diverter layer 326 adhered tothe sealing member 320 to create an upper dressing portion and a lowerdressing portion. The upper dressing portion may include the sealingmember 320, the micro-pump 316 and related components, the liquid-airseparator 330, the second internal distribution manifold 328, and thediverter layer 326. The lower dressing portion may include the absorbentlayer 310, the first internal distribution manifold 324, the sealinglayer 322, and the interface distribution manifold 308. The wireless,reduced-pressure dressing 304 may be configured to allow replacement ofthe lower dressing portion once the wireless, reduced-pressure dressinghas absorbed a maximum capacity of fluid. The upper dressing portion maybe reused after the lower dressing portion is replaced. This allowsmultiple uses of the micro-pump 316, while disposable portions of thedressing may be replaced. In another illustrative embodiment, themicro-pump 316, first processor 314, and RFID antenna 312 may be removedfrom the dressing for reuse and the remaining layers of the dressingreplaced. In still another illustrative embodiment, only the absorbentlayer 310 may be replaced. In yet another illustrative embodiment, onlythe absorbent layer 310 and the interface distribution manifold 308 maybe replaced.

The charcoal filter 332 may be utilized in the wireless,reduced-pressure dressing 304 to reduce odors created by the tissue site302 and dispersed from the wireless, reduced-pressure dressing 304. Thecharcoal filter 332 may be disposed above a valve or other output ventfrom the micro-pump 316 to filter exhaust from the micro-pump 316 priorto being released from the integrated reduced-pressure dressing 304. Itshould be understood that the charcoal filter 332 may be alternativelyconfigured and disposed above or below the micro-pump 316. In anotherillustrative embodiment, rather than using a charcoal filter, charcoalmay be integrated into any or all of the different layers utilized inthe integrated reduced-pressure dressing 304.

According to one illustrative embodiment, in operation, thereduced-pressure system 300 of FIGS. 9-11, is applied by placing theinterface distribution manifold 308 proximate to the tissue site 302.Placing the sealing layer 322 over the interface distribution manifold308 such that the aperture 323 is over the interface distributionmanifold 308. The first internal distribution manifold 324 is placedadjacent to the first interface distribution manifold 308 and possibly aportion of the sealing layer 322. The absorbent layer 310 is placedadjacent to the first internal distribution manifold 324. The diverterlayer 326 may be placed over all the components thus presented. Then thesecond internal distribution manifold 328 may be placed adjacent to aportion of the diverter layer 326 along with the liquid-air separator330. The micro-pump316, RFID antenna 312, and first processor 314 may beapplied. The components mentioned here may also be pre-assembled as adressing stack.

The sealing member 320 is used to create a seal that forms a sealedspace 318. The base unit 306 is used to transmit a pump signal as beforeto the RFID antenna 312 that is received by the first processor 314 andis used to provide power to the micro-pump 316. The first processor 314may further include one or more capacitors for holding power or one ormore batteries such as a rechargeable battery. The pump signal causesreduced pressure to be developed by the micro-pump 316. The reducedpressure is transmitted to the tissue site 302 to remove fluids or toprovide reduced pressure therapy. The fluids removed from the tissuesite 302 are transmitted within the reduced-pressure dressing 304 to theabsorbent layer 310 where the fluids are retained or substantiallyretained. As will be described in connection with FIG. 12, a pressuresensing device may be included as part of the wireless, reduced-pressuredressing 304 to provide a pressure message signal to the base unit 306.

Referring now primarily to FIG. 12, another illustrative embodiment of areduced-pressure system 300 is presented. As before, thereduced-pressure system 300 includes a wireless, reduced-pressuredressing 304 and a base unit 306. The reduced-pressure system 300 inFIG. 12 is analogous to the system presented in FIGS. 9-11, except thatthe wireless, reduced-pressure dressing 304 includes fewer componentsand includes the addition of a pressure sensing device 340 that iselectrically coupled to the first processor 314. In addition, anoptional battery 342 is included. The battery 342 may supplement powerprovided through the RFID antenna 312 or may be used as the primarypower source and then recharged by the RFID antenna 312. The RFIDantenna 312 receives power from the base unit 306. The sealing member320 is shown secured to the epidermis 344 by an attachment device 346.Components included in the previous dressing of FIGS. 9-11 have beenassigned the same reference numerals and are not necessarily discussedfurther here.

According to an illustrative embodiment, in operation, thereduced-pressure system 300 of FIG. 12 may be used by first applying theinterface distribution manifold 308 adjacent to the tissue site 302. Theabsorbent layer 310 is placed in fluid communication with the interfacedistribution manifold 308. The liquid-air separator 330 may be placedover the absorbent layer 310. Then the RFID antenna 312, pressuresensing device 340, first processor 314, micro-pump 316, and battery 342are disposed on the liquid-air separator 330. Alternatively, only someof the components, such as the micro-pump 316, may be adjacent to theliquid-air separator 330. The sealing member 320 is applied over thetissue site 302 to create a sealed space 318 and to cover all theaforementioned components. The previously mentioned components may beentirely or partially preassembled. The base unit 306 transmits a pumpsignal or pump activation signal to the reduced-pressure dressing 304that activates the micro-pump 316. The micro-pump 316 removes air orother fluids from the sealed space 318 and thereby initiates treatmentof the tissue site 302 with reduced pressure.

In addition to providing the pump activation signal or pump signal fromthe base unit 306 to the RFID antenna 312, the base unit 306 may alsotransmit a pressure inquiry signal. Upon receiving the pressure inquirysignal, the RFID antenna 312, the first processor 314, and the pressuresensing device 340 develop a pressure message signal that is transmittedby the RFID antenna to the RFID reader (not explicitly shown) of thebase unit 306. The base unit 306 may include a processor (not explicitlyshown) that receives the pressure message signal and develops a pumpcontrol signal to activate or deactivate the micro-pump 316. If thereduced pressure is in the desired therapy range, the micro-pump 316 maybe deactivated. Similarly, if the pressure is too great on an absolutescale, the base unit 306 may transmit a pump signal that activates orcontinues the micro-pump 316 to produce more reduced pressure. If morethan a sufficient elapsed time has passed without the desired pressurebeing reached, an alarm may be triggered by the base unit 306. Thewireless, reduced-pressure dressing 304 may include a galvanic cell (notexplicitly shown) to provide a full indication message signal whenexudate or other body fluids electrically couple two electrodes. Thefull indication message signal would be transmitted with the RFIDantenna 312 to the base unit 306 indicating that the dressing is full.

Referring now primarily to FIG. 13, another illustrative embodiment of areduced-pressure dressing 400 is presented that includes a wireless,reduced-pressure pump 430. The reduced-pressure dressing 400 is shown inan exploded view over a tissue site 402, such as a wound, on a patient404. The reduced-pressure dressing 400 includes an interfacedistribution manifold 406, which is disposed proximate the tissue site402. The interface distribution manifold 406 may be formed from anymanifold material, such as a GranuFoam® material or any other manifoldmaterial previously mentioned.

The reduced-pressure dressing 400 further includes a lower drape ordiverter 408. The lower drape 408 may be a polyethylene material havingadhesive on a lower side (tissue-facing side) that adheres to thepatient 404 surrounding the tissue site 402 being treated. The lowerdrape 408 includes apertures or perforations for communicating reducedpressure through the interface distribution manifold 406 to the tissuesite 402 and drawing wound fluids (liquids or gases) from the tissuesite 402. The lower drape 408 may also include a sealing ring 410 toprovide additional adhesive strength to maintain the reduced pressure ata desired therapeutic level. A protective release liner 412 mayinitially cover the sealing ring 410. The protective release liner 412is removed from the lower side of the lower drape 408 before the lowerdrape 408 is positioned on the patient 404.

The reduced-pressure dressing 400 includes an absorbent layer 414 thatmay be a non-woven fabric for absorbing the wound liquids being drawnthrough the apertures of the lower drape 408. The absorbent layer 414 issandwiched between two wicking layers 416, 418 that wick and manifoldthe wound fluid to the absorbent layer 414. The dense side of thewicking layers 416, 418 face away from the absorbent layer 414. Thewicking layers 416, 418 sandwich the absorbent layer 414 to form a fluidstorage device 420.

The reduced-pressure dressing 400 further includes an upper drape 422that may be a non-porous, occlusive barrier formed of polyethylene. Thesmooth side of the upper drape 422 faces the upper wicking layer 416.The upper drape 422 includes a aperture or opening 424. The aperture oropening 424 is covered by a hydrophobic filter 426 that separates airfrom liquid to contain the wound liquids or exudates within theabsorbent layer 414. The hydrophobic filter 426 simultaneously permitsthe flow of gas from the absorbent layer 414 as a result of reducedpressure being applied to the hydrophobic filter 426. The upper drape422 and the hydrophobic filter 426 comprise a top layer 428 of thereduced-pressure dressing 400 that covers the fluid storage device 420.All the elements of the dressing assembly described above except therelease liner 412 may be referred to collectively as the “wounddressing” portion of the reduced-pressure dressing 400.

The reduced-pressure dressing 400 further includes the wireless,reduced-pressure pump, or pump portion 430. The pump portion 430includes a micro-pump assembly 432 positioned on top of the upper drape422 to provide a reduced pressure for drawing air through thehydrophobic filter 426, the fluid storage device 420, and the interfacedistribution manifold 406. The micro-pump assembly 432 includes apiezoelectric disc pump 434 that vibrates at a predetermined frequencyto generate a desired reduced pressure at the input of the piezoelectricdisc pump 434. The piezoelectric disc pump 434 may be analogous tomicro-pump 316 of FIG. 12. The piezoelectric disc pump 434 of themicro-pump assembly 432 may not operate if any liquid drawn from thetissue site 402 into the absorbent layer 414 below the upper drape 422enters the input port of the piezoelectric disc pump 434. Thehydrophobic filter 426 prevents wound liquids or exudates from flowinginto the piezoelectric disc pump 434 of the micro-pump assembly 432.

The reduced-pressure dressing 400 may also include a spacing ring orring seal 436 positioned between the hydrophobic filter 426 and theinlet of the piezoelectric disc pump 434 to provide a cavity for airflow to the piezoelectric disc pump 434 of the micro-pump assembly 432.The micro-pump assembly 432 may be sandwiched between a first foamcushion 438 and second foam cushion 440. The micro-pump assembly 432,first cushion 438, and second cushion 440 are sandwiched between anouter ply 442 and an inner ply 444 and form a single composite packagethat is removably attached to the upper drape 422. The outer ply 442includes apertures or perforations 446 that provide an exhaust path forthe output of the micro-pump assembly 432.

The piezoelectric disc pump 434 or other micro-pump may be controlled bya first processor 448 and other control electronics. The piezoelectricdisc pump 434 may be powered by a first power unit 450 and a secondpower unit 452. The power units 450, 452 may be batteries. In anotherillustrative, embodiment, the first power unit 450 or the second powerunit 452 may comprise a RFID antenna that provides power to the firstprocessor 448 and to the piezoelectric disc pump 434.

Although the present invention and its advantages have been disclosed inthe context of certain illustrative, non-limiting embodiments, it shouldbe understood that various changes, substitutions, permutations, andalterations can be made without departing from the scope of theinvention as defined by the appended claims. It will be appreciated thatany feature that is described in connection to any one embodiment mayalso be applicable to any other embodiment.

It will be understood that the benefits and advantages described abovemay relate to one embodiment or may relate to several embodiments. Itwill further be understood that reference to “an” item refers to one ormore of those items.

The steps of the methods described herein may be carried out in anysuitable order, or simultaneously where appropriate.

Where appropriate, aspects of any of the embodiments described above maybe combined with aspects of any of the other embodiments described toform further examples having comparable or different properties andaddressing the same or different problems.

It will be understood that the above description of preferredembodiments is given by way of example only and that variousmodifications may be made by those skilled in the art. The abovespecification, examples and data provide a complete description of thestructure and use of exemplary embodiments of the invention. Althoughvarious embodiments of the invention have been described above with acertain degree of particularity, or with reference to one or moreindividual embodiments, those skilled in the art could make numerousalterations to the disclosed embodiments without departing from thescope of the claims.

1. A system for treating a tissue site with reduced pressure, the systemcomprising: a dressing for disposing proximate to the tissue site, thedressing comprising an interface distribution manifold for placingproximate to the tissue site and a dressing sealing member; pump fluidlycoupled to the dressing, the pump comprising: a RFID antenna, a firstprocessor coupled to the RFID antenna, a micro-pump device coupled tothe first processor for receiving power therefrom and developing reducedpressure, a first pump-sealing member and a second pump-sealing member,wherein the first pump-sealing member and the second pump-sealing memberare at least partially coupled to form a pump pouch in which themicro-pump device is disposed, and a fluid reservoir fluidly coupled tothe micro-pump device; a base unit having a RFID reader; and wherein theRFID reader is configured to provide power to the RFID antenna such thatthe micro-pump device is powered.
 2. (canceled)
 3. The system of claim1, wherein the pump has no source of power other than the RFID antenna.4. The system of claim 1, wherein the pump further comprises a pressuresensing device fluidly coupled to the dressing and to the firstprocessor for sensing pressure at the tissue site.
 5. The system ofclaim 1, wherein: the pump further comprises a pressure sensing devicecoupled to the first processor, the base unit comprises a secondprocessor coupled to the RFID reader, and the second processor and RFIDreader are configured to transmit a pressure inquiry signal to the firstprocessor of the pump and to receive in response thereto a pressuremessage signal from the first processor.
 6. The system of claim 1,wherein: the pump further comprises a pressure sensing device coupled tothe first processor, the base unit comprises a second processor coupledto the RFID reader, the second processor and RFID reader are configuredto transmit a pressure inquiry signal to the first processor of the pumpand to receive in response thereto a pressure message signal from thefirst processor, the first processor and pressure sensing device areconfigured to prepare the pressure message signal in response to thepressure inquiry signal, the first processor and RFID antenna areconfigured to transmit the pressure message signal, and the secondprocessor is configured to receive the pressure message signal, preparea control signal, and the second processor and RFID are configured totransmit the control signal to the pump to provide a control signal foractivating or deactivating the micro-pump device.
 7. The system of claim1, wherein: the pump further comprises a pressure sensing device coupledto the first processor, the pressure sensing device is operable toproduce a pressure message signal, and the first processor is operableto receive the pressure message signal and to produce a control signalto activate or deactivate the micro-pump device.
 8. (canceled) 9.(canceled)
 10. (canceled)
 11. (canceled)
 12. (canceled)
 13. A method ofmanufacturing a reduced-pressure system for treating a tissue site, themethod comprising: providing a dressing for disposing proximate to thetissue site, the dressing comprising an interface distribution manifoldfor placing proximate to the tissue site and a dressing sealing member;providing a pump, the pump comprising: a RFID antenna, a first processorcoupled to the RFID antenna, a micro-pump device coupled to the firstprocessor for receiving power therefrom and developing reduced pressure,a first pump-sealing member and a second pump-sealing member, whereinthe first pump-sealing member and the second pump-sealing member are atleast partially coupled to form a pump pouch in which the micro-pumpdevice is disposed, and a fluid reservoir fluidly coupled to themicro-pump device; providing a base unit having a RFID reader; andwherein the RFID reader is configured to provide power to the RFIDantenna such that the micro-pump device is powered.
 14. (canceled) 15.The method of manufacturing of claim 13, further comprising providing areduced-pressure conduit for fluidly coupling the pump to the dressing.16. The method of manufacturing of claim 13, further comprisingproviding a pressure sensing device and coupling the pressure sensingdevice to the dressing.
 17. A method for treating a tissue site withreduced pressure, the method comprising: placing a dressing proximate tothe tissue site, the dressing comprising an interface distributionmanifold for placing proximate to the tissue site and a dressing sealingmember; providing a pump, wherein the pump comprises: a RFID antenna, afirst processor coupled to the RFID antenna, a micro-pump device coupledto the first processor for receiving power therefrom and developingreduced pressure, a first pump-sealing member and a second pump-sealingmember, wherein the first pump-sealing member and the secondpump-sealing member are at least partially coupled to form a pump pouchin which the micro-pump device is disposed, and a fluid reservoirfluidly coupled to the micro-pump device; fluidly coupling the pump tothe dressing; providing a base unit having a RFID reader and a secondprocessor; and transmitting an activation signal from the secondprocessor to the pump to activate the pump.
 18. (canceled)
 19. Themethod of claim 17, wherein all the power required by the micro-pumpdevice is delivered by the RFID reader.
 20. The method of claim 17,further comprising the step of placing the RFID reader within five (5)centimeters of the RFID antenna of the pump.
 21. The method of claim 17,wherein the pump has no source of power other than the RFID antenna; thepump further comprising: a pressure sensing device fluidly coupled tothe dressing and to the first processor for sensing pressure at thetissue site, a first distribution manifold, an absorbent layer, and adiverter layer, wherein the first distribution manifold, the absorbentlayer, and the diverter layer are disposed within the pump pouch formedby the first pump-sealing member and the second pump-sealing member, andwherein the micro-pump device comprises a piezoelectric pump; and thedressing further comprising: a reduced-pressure interface. 22.(canceled)
 23. (canceled)
 24. (canceled)
 25. (canceled)
 26. (canceled)27. (canceled)
 28. (canceled)
 29. A pump, comprising: a RFID antenna; afirst processor coupled to the RFID antenna; a micro-pump device coupledto the first processor for receiving power therefrom and developingreduced pressure; a first pump-sealing member and a second pump-sealingmember, wherein the first pump-sealing member and the secondpump-sealing member are at least partially coupled to form a pump pouchin which the micro-pump device is disposed; and wherein the pump isadapted to be fluidly coupled to a dressing, the dressing comprising aninterface distribution manifold for placing proximate to a tissue siteand a dressing sealing member.
 30. The pump of claim 29, furthercomprising a fluid reservoir fluidly coupled to the micro-pump device.31. (canceled)
 32. The pump of claim 29, wherein the pump has no sourceof power other than the RFID antenna.
 33. The pump of claim 29, whereinthe pump further comprises a pressure sensing device fluidly coupled tothe dressing and to the first processor for sensing pressure at thetissue site.
 34. The pump of claim 29, wherein the pump furthercomprises a pressure sensing device coupled to the first processor;further comprising a base unit that comprises a second processor coupledto a RFID reader; and wherein the second processor and the RFID readerare configured to transmit a pressure inquiry signal to the firstprocessor of the pump and to receive in response thereto a pressuremessage signal from the first processor.
 35. The pump of claim 29,wherein the pump further comprises a pressure sensing device coupled tothe first processor, further comprising a base unit that comprises asecond processor coupled to a RFID reader, wherein the second processorand the RFID reader are configured to transmit a pressure inquiry signalto the first processor of the pump and to receive in response thereto apressure message signal from the first processor, wherein the firstprocessor and pressure sensing device are configured to prepare thepressure message signal in response to the pressure inquiry signal,wherein the first processor and the RFID antenna are configured totransmit the pressure message signal, and wherein the second processoris configured to receive the pressure message signal, prepare a controlsignal, and the second processor and the RFID reader are configured totransmit the control signal to the the RFID antenna to provide a controlsignal for activating or deactivating the micro-pump device.
 36. Thepump of claim 29, wherein: the pump further comprises a pressure sensingdevice coupled to the first processor, the pressure sensing device isoperable to produce a pressure message signal, and the first processoris operable to receive the pressure message signal and to produce acontrol signal to activate or deactivate the micro-pump device. 37.(canceled)
 38. (canceled)
 39. (canceled)